Solid-state imaging device and electronic apparatus

ABSTRACT

The present disclosure relates to a solid-state imaging device and an electronic apparatus that can reduce the influence on an OPB pixel in a case where blooming has occurred in an aperture pixel. A solid-state imaging device that is one aspect of the present disclosure has a first photoelectric conversion portion, an upper electrode, and a lower electrode formed outside a substrate, the first photoelectric conversion portion performing photoelectric conversion in accordance with incident light, the upper electrode and the lower electrode being formed to sandwich the first photoelectric conversion portion. The solid-state imaging device includes: an aperture pixel that is disposed on a pixel array, and generates a normal pixel signal; an OPB pixel that is disposed at an end portion on the pixel array, and generates a pixel signal indicating a dark current component; and a charge releasing portion that is disposed between the aperture pixel and the OPB pixel, and releases electric charge flowing out from the aperture pixel. The present disclosure can be applied to back-illuminated vertical spectroscopic CMOS image sensors.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Phase of International PatentApplication No. PCT/JP2017/010864 filed on Mar. 17, 2017, which claimspriority benefit of Japanese Patent Application No. JP 2016-070059 filedin the Japan Patent Office on Mar. 31, 2016. Each of theabove-referenced applications is hereby incorporated herein by referencein its entirety.

TECHNICAL FIELD

The present disclosure relates to a solid-state imaging device and anelectronic apparatus, and more particularly, to a solid-state imagingdevice that has a dummy pixel disposed between an aperture pixel forgenerating a normal pixel signal and an optical black (OPB) pixel forgenerating a pixel signal indicating a dark current component, and anelectronic apparatus.

BACKGROUND ART

There is a known conventional configuration in which a large number ofpixels arranged in rows and columns in a pixel array are divided intoaperture pixels, OPB pixels, and dummy pixels in a solid-state imagingdevice such as a CMOS image sensor (see Patent Document 1, for example).

In this specification, an aperture pixel, an OPB pixel, and a dummypixel are defined as follows.

An aperture pixel is a pixel that is open without any light shieldingfilm on the light incident surface side, and generates a pixel signal byperforming photoelectric conversion in accordance with incident light.Normally, such an aperture pixel is also called an effective pixel or anormal pixel. An OPB pixel is a pixel that has a light shielding filmformed on the light incident surface side so that incident light isblocked, and generates a pixel signal indicating the dark currentcomponent in a state where there is no incident light. A dummy pixel isa pixel formed between an aperture pixel and an OPB pixel, to reduce theinfluence on the OPB pixel in a case where blooming has occurred in theaperture pixel.

FIG. 1 shows a first conventional example indicating the configurationof a solid-state imaging device in which a dummy pixel is formed betweenan aperture pixel and an OPB pixel.

In this solid-state imaging device 10, an aperture pixel 11 is disposedin the central region of a pixel array, an OPB pixel 12 is disposed inthe marginal region, and a dummy pixel 13 is disposed between theaperture pixel 11 and the OPB pixel 12.

In the solid-state imaging device 10, a Si substrate 14 and a wiringlayer 17 are stacked as a configuration to be shared by the aperturepixel 11, the OPB pixel 12, and the dummy pixel 13, and photodiodes(PDs) 15 that perform photoelectric conversion and floating diffusions(FDs) 16 that temporarily store electric charges are formed in the Sisubstrate 14. In the wiring layer 17, transfer gates 18 for transferringelectric charges from the PDs 15 to the FDs 16 are formed.

A light shielding film 19 is formed on the light incident surface sideof the OPB pixel 12 and the dummy pixel 13. Meanwhile, the lightincident surface side of the aperture pixel 11 is not shielded fromlight, but is open.

The dummy pixel 13 is provided with a connecting portion 20 thatconnects the PD 15 directly to a Vdd wiring line.

In the dummy pixel 13 of the solid-state imaging device 10, the PD 15 isfixed at a constant voltage (Vdd in this case). Accordingly, in a casewhere blooming occurs in the aperture pixel 11, the electric chargesthat have flowed into the PD 15 can be released to the Vdd wiring line.

FIG. 2 shows a second conventional example indicating the configurationof a solid-state imaging device in which a dummy pixel is formed betweenan aperture pixel and an OPB pixel.

In this solid-state imaging device 30, an aperture pixel 31 is disposedin the central region of a pixel array, an OPB pixel 32 is disposed inthe marginal region, and a dummy pixel 33 is disposed between theaperture pixel 31 and the OPB pixel 32.

In the solid-state imaging device 30, a Si substrate 14 and a wiringlayer 17 are stacked as a configuration to be shared by the aperturepixel 31, the OPB pixel 32, and the dummy pixel 33. In the Si substrate14, PDs 15 that perform photoelectric conversion, and FDs 16 thattemporarily store electric charges transferred from the PDs 15 areformed. In the wiring layer 17, transfer gates 18 for transferringelectric charges from the PDs 15 to the FDs 16 are formed.

A light shielding film 19 is formed on the light incident surface sideof the OPB pixel 32 and the dummy pixel 33. Meanwhile, the lightincident surface side of the aperture pixel 31 is not shielded fromlight, but is open.

In the dummy pixel 33, a connecting portion 34 that connects the FD 16and the PD 15 is provided under the transfer gate 18.

In the dummy pixel 33 of the solid-state imaging device 30, the FD 16and the PD 15 of a high potential are connected by the connectingportion 34. Accordingly, in a case where blooming occurs in the aperturepixel 31, the electric charges that have flowed into the PD 15 can bereleased through the FD 16.

CITATION LIST Patent Document

Patent Document 1: Japanese Patent Application Laid-Open No. 2008-103472

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

The dummy pixel 13 in the first conventional example and the dummy pixel33 in the second conventional example described above can be applied incases where the PD 14 as a photoelectric conversion portion is formedinside the Si substrate 14, but cannot be used in configurations inwhich an organic photoelectric conversion film or the like serving as aphotoelectric conversion portion is formed outside the Si substrate 14.

The present disclosure is made in view of such circumstances, and is toreduce the influence on an OPB pixel in a case where blooming hasoccurred in an aperture pixel in a configuration having a photoelectricconversion portion formed outside a Si substrate.

Solutions to Problems

A solid-state imaging device that is a first aspect of the presentdisclosure has a first photoelectric conversion portion, an upperelectrode, and a lower electrode formed outside a substrate, the firstphotoelectric conversion portion performing photoelectric conversion inaccordance with incident light, the upper electrode and the lowerelectrode being formed to sandwich the first photoelectric conversionportion. The solid-state imaging device includes: an aperture pixel thatis disposed on a pixel array, and generates a normal pixel signal; anOPB pixel that is disposed at an end portion on the pixel array, andgenerates a pixel signal indicating a dark current component; and acharge releasing portion that is disposed between the aperture pixel andthe OPB pixel, and releases electric charge flowing out from theaperture pixel.

The charge releasing portion may be a dummy pixel disposed between theaperture pixel and the OPB pixel, and the lower electrode correspondingto the dummy pixel may be fixed at a constant voltage.

The lower electrode corresponding to the dummy pixel may be connected toa power supply voltage wiring line.

The lower electrode corresponding to the dummy pixel may be connected toa power supply voltage wiring line via a control transistor that isalways on.

At least one of the dummy pixel may be disposed between the aperturepixel and the OPB pixel.

The dummy pixel may be disposed to surround the region where theaperture pixel is disposed.

The charge releasing portion may be formed with the lower electrodefixed at a constant voltage.

The charge releasing portion formed with the lower electrode fixed at aconstant voltage may be disposed around each aperture pixel.

The solid-state imaging device that is the first aspect of the presentdisclosure may further include a second photoelectric conversion portionthat is formed in the substrate, and has a different wavelength band forphotoelectric conversion from that of the first photoelectric conversionportion.

The second photoelectric conversion portion corresponding to the dummypixel may be connected to a power supply voltage wiring line.

The second photoelectric conversion portion corresponding to the dummypixel may be connected to an FD via a control transistor that is alwayson.

The solid-state imaging device that is the first aspect of the presentdisclosure may further include a third photoelectric conversion portionthat is formed in the substrate, and has a different wavelength band forphotoelectric conversion from those of the first and secondphotoelectric conversion portions.

The third photoelectric conversion portion corresponding to the dummypixel may be connected to a power supply voltage wiring line.

The third photoelectric conversion portion corresponding to the dummypixel may be connected to an FD via a control transistor that is alwayson.

The solid-state imaging device that is the first aspect of the presentdisclosure may further include a light shielding portion that shieldsthe charge releasing portion and the OPB pixel from light.

The solid-state imaging device may be of a back-illuminated type.

An electronic apparatus that is a second aspect of the presentdisclosure includes a solid-state imaging device having a firstphotoelectric conversion portion, an upper electrode, and a lowerelectrode formed outside a substrate, the first photoelectric conversionportion performing photoelectric conversion in accordance with incidentlight, the upper electrode and the lower electrode being formed tosandwich the first photoelectric conversion portion. The solid-stateimaging device includes: an aperture pixel that is disposed on a pixelarray, and generates a normal pixel signal; an OPB pixel that isdisposed at an end portion on the pixel array, and generates a pixelsignal indicating a dark current component; and a charge releasingportion that is disposed between the aperture pixel and the OPB pixel,and releases electric charge flowing out from the aperture pixel.

In the first and second aspects of present disclosure, electric chargesthat have flowed out from an aperture pixel are released by a chargereleasing portion disposed between the aperture pixel and an OPB pixel.

Effects of the Invention

According to the first and second aspects of the present disclosure, itis possible to reduce the influence on an OPB pixel in a case whereblooming has occurred in an aperture pixel.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram showing a first conventional example of asolid-state imaging device.

FIG. 2 is a block diagram showing a second conventional example of asolid-state imaging device.

FIGS. 3A and 3B are diagrams showing a first example configuration of asolid-state imaging device to which the present disclosure is applied.

FIG. 4 is a diagram showing a modification of the first exampleconfiguration of a solid-state imaging device.

FIG. 5 is a diagram showing a second example configuration of asolid-state imaging device to which the present disclosure is applied.

FIG. 6 is a diagram showing a third example configuration of asolid-state imaging device to which the present disclosure is applied.

FIG. 7 is a diagram showing a first modification of the third exampleconfiguration of a solid-state imaging device.

FIG. 8 is a diagram showing a second modification of the third exampleconfiguration of a solid-state imaging device.

FIG. 9 is a diagram showing a fourth example configuration of asolid-state imaging device to which the present disclosure is applied.

FIG. 10 is a diagram showing a fifth example configuration of asolid-state imaging device to which the present disclosure is applied.

FIG. 11 is a diagram showing a sixth example configuration of asolid-state imaging device to which the present disclosure is applied.

FIG. 12 is a diagram showing a seventh example configuration of asolid-state imaging device to which the present disclosure is applied.

FIG. 13 is a diagram showing examples of use of solid-state imagingdevices to which the present disclosure is applied.

MODE FOR CARRYING OUT THE INVENTION

The following is a detailed description of the best modes for carryingout the present disclosure (these modes will be hereinafter referred toas the embodiments), with reference to the drawings.

First Embodiment

FIGS. 3A and 3B show a first example configuration (a first embodiment)of a solid-state imaging device to which present disclosure is applied.FIG. 3A is a cross-sectional view, and FIG. 3B is a graph of thepotential corresponding to the line segment X-X′ shown in FIG. 3A.

Note that, in the respective embodiments described below, the samecomponents as those of the first and second conventional examples aredenoted by the same reference numerals as those used in the first andsecond conventional examples, and explanation of them is notunnecessarily repeated herein.

In this solid-state imaging device 40, an aperture pixel 41 is disposedin the central region of a pixel array, an OPB pixel 42 is disposed inthe marginal region, and a dummy pixel 43 is disposed between theaperture pixel 41 and the OPB pixel 42. Note that, although only onedummy pixel 43 is formed between the aperture pixel 41 and the OPB pixel42 in this case illustrated in the drawing, two or more dummy pixels 43may be formed between the aperture pixel 41 and the OPB pixel 42. Thesame applies in each of the embodiments described later.

The solid-state imaging device 40 has a structure in which a Sisubstrate 14, a wiring layer 17, and an organic photoelectric conversionfilm 51 are stacked in this order from the lower layer side as aconfiguration to be shared by the aperture pixel 41, the OPB pixel 42,and the dummy pixel 43. Upper electrodes 52 and lower electrodes 53 forapplying voltage to the organic photoelectric conversion film 51 areformed on and under the organic photoelectric conversion film 51. In theSi substrate 14, FDs 54 that temporarily store electric chargestransferred from the organic photoelectric conversion film 51 via thelower electrodes 53 are formed. The FDs 54 are connected to the lowerelectrodes 53. In the wiring layer 17, in addition to various wiringlines, reset gates 55 for resetting the voltage of the FDs 54 areformed. A specific voltage supply line for applying a reset voltage or apredetermined discharge voltage is connected to the reset gates 55connected to the FDs 54. The voltage to be supplied by the specificvoltage supply line is 0 V, for example.

In the solid-state imaging device 40, as a result of an exposureoperation, holes are read as signal charges, through the lowerelectrodes 53, out of the electron-hole pairs generated by the organicphotoelectric conversion film 51.

A light shielding film 19 is formed on the light incident surface sideof the OPB pixel 42 and the dummy pixel 43. Meanwhile, the lightincident surface side of the aperture pixel 41 is not shielded fromlight, but is open.

Prior to the exposure operation, the solid-state imaging device 40resets the aperture pixel 41 and the OPB pixel 42. At the time ofresetting, the resetting is performed so that the potentials of thelower electrodes 53 and the FDs 54 become lower than the potential ofthe upper electrodes 52. For example, the same positive voltage isapplied to the upper electrodes 52 of the aperture pixel 41, the OPBpixel 42, and the dummy pixel 43, and the reset gates 55 of the aperturepixel 41 and the OPB pixel 42 are put into an active state, so that thelower electrodes 53 and the FDs 54 are reset to the reset voltage (0 V).In the dummy pixel 43 of the solid-state imaging device 40, the resetgate 55 corresponding to the organic photoelectric conversion film 51 isalways on, and the FD 54 and the lower electrode 53 are fixed at thedischarge voltage. The discharge voltage may be the same voltage as thereset voltage (0 V).

After the lower electrodes 53 and the FDs 54 are reset, the reset gates55 are put into an inactive state (in other words, closed), so that thereset operation is terminated, and an exposure operation (in otherwords, a charge storage operation) is started. During the exposureoperation period, the same positive voltage is applied to the upperelectrodes of the aperture pixel 41, the OPB pixel 42, and the dummypixel 43, as in the reset operation period.

Since the reset gates 55 are closed during the exposure operationperiod, the holes generated as a result of light incidence are stored inthe lower electrode 53 and the FD 54 in the aperture pixel 41. Becauseof this, the potentials of the lower electrode 53 and the FD 54 becomehigher than the reset voltage.

Note that, in the OPB pixel 42 shielded from incident light by the lightshielding film 19, the potential of the lower electrode 53 is apotential reflecting the magnitude of noise such as dark currentgenerated during the exposure operation period.

In the dummy pixel 43, the reset gate 55 corresponding to the organicphotoelectric conversion film 51 is always on, and accordingly, the FD54 and the lower electrode 53 are also fixed at the discharge voltage (0V) during the exposure operation period.

In a case where excessive light enters the aperture pixel 41 during theexposure period, on the other hand, the holes generated in the aperturepixel 41 are stored in the lower electrode 53 and the FD 54 of thepixel, and further, a phenomenon that the holes flow into the lowerelectrode of an adjacent pixel, or blooming, might occur.

In the solid-state imaging device 40, however, even if excessive lightenters the outermost aperture pixel 41 among aperture pixels 41 arrangedin an array, and blooming occurs, the extra generated holes flow intothe lower electrode 53 of the dummy pixel 43, and are released to thespecific voltage supply line via the FD 54 and the reset gate 55. Thus,the electric charges that have flowed out from the aperture pixel 41 canbe prevented from flowing into the OPB pixel 42.

Furthermore, the potential is high between the lower electrode 53 of thedummy pixel 43 and the lower electrode 53 of the OPB pixel 42. Thus,holes can be prevented from flowing out from the lower electrode 53 ofthe dummy pixel 43 and flowing into the lower electrode 53 of the OPBpixel 42.

FIG. 4 shows a modification of the solid-state imaging device 40. Inthis modification, a dummy pixel 43 is disposed between an aperturepixel 41 and an OPB pixel 42, and dummy pixels 43 are further disposedon the right side and the lower side on which any OPB pixel 42 is notdisposed in the drawing. In this arrangement, the dummy pixels 43surround the region of the aperture pixels 41. Thus, the electriccharges from the aperture pixels 41 can be prevented from flowing to theoutside of the dummy pixels 43.

Note that the modification shown in FIG. 4 can also be applied to eachof the embodiments described later.

Second Embodiment

In addition, FIG. 5 shows a cross-sectional view of a second exampleconfiguration (a second embodiment) of a solid-state imaging device towhich present disclosure is applied.

In this solid-state imaging device 60, an aperture pixel 61 is disposedin the central region of a pixel array, an OPB pixel 62 is disposed inthe marginal region, and a dummy pixel 63 is disposed between theaperture pixel 61 and the OPB pixel 62.

The solid-state imaging device 60 has a structure in which a Sisubstrate 14, a wiring layer 17, and an organic photoelectric conversionfilm 51 are stacked in this order from the lower layer side as aconfiguration to be shared by the aperture pixel 61, the OPB pixel 62,and the dummy pixel 63. Upper electrodes 52 and lower electrodes 53 forapplying voltage to the organic photoelectric conversion film 51 areformed on and under the organic photoelectric conversion film 51. In theSi substrate 14, FDs 54 connected to the lower electrodes 53 are formed.

Reset gates 55 for resetting the voltage of the FDs 54 to the resetvoltage (0 V) are formed in the wiring layer 17 of the aperture pixel 61and the OPB pixel 62.

On the other hand, a connecting portion 64 for connecting the lowerelectrode 53 and the FD 54 to a Vss wiring line is formed in the wiringlayer 17 of the dummy pixel 63.

A light shielding film 19 is formed on the light incident surface sideof the OPB pixel 62 and the dummy pixel 63. Meanwhile, the lightincident surface side of the aperture pixel 61 is not shielded fromlight, but is open.

In the dummy pixel 63 of the solid-state imaging device 60, the FD 54and the lower electrode 53 are fixed at a constant voltage (Vss). On theother hand, in a case where blooming occurs, holes are stored in thelower electrode 53 of the aperture pixel 61, and therefore, thepotential becomes higher than Vss. As a result, the holes stored in thelower electrode 53 of the aperture pixel 61 flow into the lowerelectrode 53 of the dummy pixel 63, and are released to the Vss wiringline via the FD 54 and the connecting portion 64. Thus, the electriccharges that have flowed out from the aperture pixel 61 can be preventedfrom flowing into the OPB pixel 62.

Furthermore, the potential is high between the lower electrode 53 of thedummy pixel 63 and the lower electrode 53 of the OPB pixel 62. Thus,holes can be prevented from flowing out from the lower electrode 53 ofthe dummy pixel 63 and flowing into the lower electrode 53 of the OPBpixel 62.

Third Embodiment

In addition, FIG. 6 shows a cross-sectional view of a third exampleconfiguration (a third embodiment) of a solid-state imaging device towhich present disclosure is applied.

In this solid-state imaging device 70, an aperture pixel 71 is disposedin the central region of a pixel array, and OPB pixels 72 are disposedin the marginal region. Note that the OPB pixel 72 adjacent to theaperture pixel 71 is specifically referred to as the OPB pixel 72′.

The solid-state imaging device 70 has a structure in which a Sisubstrate 14, a wiring layer 17, and an organic photoelectric conversionfilm 51 are stacked in this order from the lower layer side as aconfiguration to be shared by the aperture pixel 71 and the OPB pixels72. Upper electrodes 52 and lower electrodes 53 for applying voltage tothe organic photoelectric conversion film 51 are formed on and under theorganic photoelectric conversion film 51. FDs 54 are formed in the Sisubstrate 14. Reset gates 55 for resetting the voltage of the FDs 54 tothe reset voltage (0 V) are formed in the wiring layer 17.

A drain portion 73 is added to the wiring layer 17 of the OPB pixel 72′adjacent to the aperture pixel 71, and a lower electrode 74 connected tothe Vss wiring line is formed in the drain portion 73.

A light shielding film 19 is formed on the light incident surface sideof the OPB pixels 72. Meanwhile, the light incident surface side of theaperture pixel 71 is not shielded from light, but is open.

In the OPB pixel 72′ adjacent to the aperture pixel 71 of thesolid-state imaging device 70, the lower electrode 74 is fixed at aconstant voltage (Vss). On the other hand, in a case where bloomingoccurs, holes are stored in the lower electrode 53 of the aperture pixel71, and therefore, the potential becomes higher than Vss. As a result,the holes stored in the lower electrode 53 of the aperture pixel 71 arereleased to the Vss wiring line via (the lower electrode 74 of) thedrain portion 73 of the OPB pixel 72′. Thus, the electric charges thathave flowed out from the aperture pixel 41 can be prevented from flowinginto the OPB pixel 72.

Furthermore, the potential is high between the lower electrode 74 andthe lower electrode 53 of the OPB pixel 72′. Thus, holes can beprevented from flowing out from the lower electrode 74 and flowing intothe lower electrode 53 of the OPB pixel 72′.

Note that, although only one OPB pixel 72′ is formed between theaperture pixel 71 and the OPB pixel 72 in this case illustrated in thedrawing, two or more OPB pixels 72′ may be formed between the aperturepixel 71 and the OPB pixel 72.

FIG. 7 shows a first modification of the solid-state imaging device 70.In the first modification, all the pixels in the entire OPB pixel regionare OPB pixels 72′, and a drain portion 73 (in other words, a lowerelectrode 74 connected to a Vss wiring line) is formed between each twopixels. Thus, inflow of electric charges into each OPB pixel 72′ can beprevented.

FIG. 8 shows a second modification of the solid-state imaging device 70.In the second modification, a drain portion 73 (in other words, a lowerelectrode 74 connected to a Vss wiring line) is formed between each twopixels of all the aperture pixels 71. Thus, outflow of electric chargesfrom the respective aperture pixels 71 can be prevented.

Fourth Embodiment

In addition, FIG. 9 shows a cross-sectional view of a fourth exampleconfiguration (a fourth embodiment) of a solid-state imaging device towhich present disclosure is applied.

In this solid-state imaging device 80, an aperture pixel 81 is disposedin the central region of a pixel array, an OPB pixel 82 is disposed inthe marginal region, and a dummy pixel 83 is disposed between theaperture pixel 81 and the OPB pixel 82.

The solid-state imaging device 80 differs from the solid-state imagingdevice 50 shown in FIGS. 3A and 3B in that PDs 84 that performphotoelectric conversion in accordance with light of a differentwavelength from that of the organic photoelectric conversion film 51 areadded in the Si substrate 14. However, the FDs, the transfer gates, andthe like corresponding to the PDs 84 are not shown in the drawing. Theother aspects of the configuration are the same as those of thesolid-state imaging device 50.

As for the organic photoelectric conversion film 51 of the dummy pixel83 in the solid-state imaging device 80, the reset gate 55 is always on,and the FD 54 and the lower electrode 53 corresponding to the organicphotoelectric conversion film 51 are fixed at 0 V. Further, as for thePD 84 of the dummy pixel 83, the potential of the PD 84 is fixed at Vdd,the PD 84 is connected to the corresponding FD, or the transfer gatecorresponding to the PD 84 is always on, as shown in FIG. 1 or 2.

Accordingly, in a case where blooming occurs in the aperture pixel 81,the electric charges that have flowed out from the organic photoelectricconversion film 51 of the aperture pixel 81 can be released to aspecific voltage supply line via the lower electrode 53, the FD 54, andthe reset gate 55 of the dummy pixel 83. At this stage, the potential ishigh between the lower electrode 53 of the dummy pixel 83 and the lowerelectrode 53 of the OPB pixel 82. Thus, holes can be prevented fromflowing out from the lower electrode 53 of the dummy pixel 83 andflowing into the lower electrode 53 of the OPB pixel 82.

Furthermore, the electric charges that have flowed out from the PD 84 ofthe aperture pixel 81 can be released to a Vdd wiring line or thecorresponding FD via the PD 84 of the dummy pixel 83.

Thus, the electric charges that have flowed out from the aperture pixel81 can be prevented from flowing into the OPB pixel 82.

Fifth Embodiment

In addition, FIG. 10 shows a cross-sectional view of a fifth exampleconfiguration (a fifth embodiment) of a solid-state imaging device towhich present disclosure is applied.

In this solid-state imaging device 90, an aperture pixel 91 is disposedin the central region of a pixel array, an OPB pixel 92 is disposed inthe marginal region, and a dummy pixel 93 is disposed between theaperture pixel 91 and the OPB pixel 92.

The solid-state imaging device 90 differs from the solid-state imagingdevice 80 shown in FIG. 9 in that PDs 94 that perform photoelectricconversion in accordance with light of a different wavelength from thoseof the organic photoelectric conversion film 51 and the PDs 84 are addedin the Si substrate 14. However, the FDs, the transfer gates, and thelike corresponding to the PDs 94 are not shown in the drawing. The otheraspects of the configuration are the same as those of the solid-stateimaging device 80.

As for the organic photoelectric conversion film 51 of the dummy pixel93 in the solid-state imaging device 90, the reset gate 55 is always on,and the FD 54 and the lower electrode 53 corresponding to the organicphotoelectric conversion film 51 are fixed at 0 V. Further, as for thePDs 84 and 94 of the dummy pixel 93, the potential of the PDs 84 and 94is fixed at Vdd, the PDs 84 and 94 are connected to the correspondingFD, or the transfer gate corresponding to the PDs 84 and 94 is alwayson, as shown in FIG. 1 or 2.

Accordingly, in a case where blooming occurs in the aperture pixel 91,the electric charges that have flowed out from the organic photoelectricconversion film 51 of the aperture pixel 91 can be released to aspecific voltage supply line via the lower electrode 53, the FD 54, andthe reset gate 55 of the dummy pixel 93. At this stage, the potential ishigh between the lower electrode 53 of the dummy pixel 93 and the lowerelectrode 53 of the OPB pixel 92. Thus, holes can be prevented fromflowing out from the lower electrode 53 of the dummy pixel 93 andflowing into the lower electrode 53 of the OPB pixel 92.

Furthermore, the electric charges that have flowed out from the PDs 84and 94 of the aperture pixel 91 can be released to a Vdd wiring line orthe corresponding FD via the PDs 84 and 94 of the dummy pixel 93.

Thus, the electric charges that have flowed out from the aperture pixel91 can be prevented from flowing into the OPB pixel 92.

Sixth Embodiment

In addition, FIG. 11 shows a cross-sectional view of a sixth exampleconfiguration (a sixth embodiment) of a solid-state imaging device towhich present disclosure is applied. The first through fifth embodimentsdescribed above are of a surface-illuminated type. A solid-state imagingdevice 100 according to the sixth embodiment is obtained by convertingthe solid-state imaging device 80 of the fourth embodiment shown in FIG.9 into a solid-state imaging device of a back-illuminated type. As aback-illuminated type is adopted, it becomes possible to secure a highdegree of freedom in wiring and a sufficient quantity of incident light.

In this solid-state imaging device 100, an aperture pixel 101 isdisposed in the central region of a pixel array, an OPB pixel 102 isdisposed in the marginal region, and a dummy pixel 103 is disposedbetween the aperture pixel 101 and the OPB pixel 102.

The solid-state imaging device 100 has a structure in which a wiringlayer 17, a Si substrate 14, and an organic photoelectric conversionfilm 51 are stacked in this order from the lower layer side as aconfiguration to be shared by the aperture pixel 101, the OPB pixel 102,and the dummy pixel 103. Upper electrodes 52 and lower electrodes 53 forapplying voltage to the organic photoelectric conversion film 51 areformed on and under the organic photoelectric conversion film 51.

PDs 84 that perform photoelectric conversion in accordance with light ofa different wavelength from that of the organic photoelectric conversionfilm 51 is formed in the Si substrate 14. FDs 54 corresponding to theorganic photoelectric conversion film 51 and FDs 105 corresponding tothe PDs 84 are further formed in the Si substrate 14. Penetratingelectrodes 104 connected to the lower electrodes 53 are further formedin the Si substrate 14.

Reset gates 55 for resetting the FDs 54 and transfer gates 106 fortransferring electric charges converted by the PDs 84 to the FDs 105 areformed in the wiring layer 17.

A light shielding film 19 is formed on the light incident surface sideof the OPB pixel 102 and the dummy pixel 103. Meanwhile, the lightincident surface side of the aperture pixel 101 is not shielded fromlight, but is open.

In the dummy pixel 103 of the solid-state imaging device 100, the resetgate 55 is always on, and the FD 54 is fixed at 0 V. Accordingly, thelower electrode 53 connected to the FD 54 via the penetrating electrode104 is also fixed at 0 V. Further, the transfer gate 106 is also alwayson.

Accordingly, in a case where blooming occurs in the aperture pixel 101,the electric charges that have flowed out from the organic photoelectricconversion film 51 of the aperture pixel 101 flow into the lowerelectrode 53 of the dummy pixel 103, and are released to a specificvoltage supply line via the penetrating electrode 104, the FD 54, andthe reset gate 55. At this stage, the potential is high between thelower electrode 53 of the dummy pixel 103 and the lower electrode 53 ofthe OPB pixel 102. Thus, holes can be prevented from flowing out fromthe lower electrode 53 of the dummy pixel 103 and flowing into the lowerelectrode 53 of the OPB pixel 102.

Furthermore, the electric charges that have flowed out from the PD 84 ofthe aperture pixel 101 can be released to the FD 105 via the PD 84 ofthe dummy pixel 103.

Thus, the electric charges that have flowed out from the aperture pixel101 can be prevented from flowing into the OPB pixel 102.

Note that PDs that perform photoelectric conversion in accordance withlight of a different wavelength from those of the organic photoelectricconversion film 51 and the PDs 84 may be added in the Si substrate 14.In that case, with these PDs, the electric charges that have flowed outfrom the aperture pixel 101 should be released to the corresponding FDs,as with the PDs 84.

Seventh Embodiment

In addition, FIG. 12 shows a cross-sectional view of a seventh exampleconfiguration (a seventh embodiment) of a solid-state imaging device towhich present disclosure is applied.

A solid-state imaging device 120 according to the seventh embodiment isof a back-illuminated type. An aperture pixel 121 is disposed in thecentral region of a pixel array, an OPB pixel 122 is disposed in themarginal region, and a dummy pixel 123 is disposed between the aperturepixel 121 and the OPB pixel 122.

The solid-state imaging device 120 differs from the solid-state imagingdevice 100 shown in FIG. 11 in that a connecting portion 124 thatconnects the PD 84 directly to the Vdd wiring line is added to the dummypixel 123.

In the dummy pixel 123 of the solid-state imaging device 120, the resetgate 55 is always on, and the FD 54 is fixed at 0 V. Accordingly, thelower electrode 53 connected to the FD 54 via the penetrating electrode104 is also fixed at 0 V. Further, the potential of the PD 84 is fixedat Vdd.

Accordingly, in a case where blooming occurs in the aperture pixel 121,the electric charges that have flowed out from the organic photoelectricconversion film 51 of the aperture pixel 121 flow into the lowerelectrode 53 of the dummy pixel 123, and are released to a specificvoltage supply line via the penetrating electrode 104, the FD 54, andthe reset gate 55. At this stage, the potential is high between thelower electrode 53 of the dummy pixel 123 and the lower electrode 53 ofthe OPB pixel 122. Thus, holes can be prevented from flowing out fromthe lower electrode 53 of the dummy pixel 123 and flowing into the lowerelectrode 53 of the OPB pixel 122.

Furthermore, the electric charges that have flowed out from the PD 84 ofthe aperture pixel 121 can be released to the Vdd wiring line via the PD84 of the dummy pixel 123.

Thus, the electric charges that have flowed out from the aperture pixel121 can be prevented from flowing into the OPB pixel 42.

Note that PDs that perform photoelectric conversion in accordance withlight of a different wavelength from those of the organic photoelectricconversion film 51 and the PDs 84 may be added in the Si substrate 14.In that case, with these PDs, the electric charges that have flowed outfrom the aperture pixel 121 should be released to the corresponding FDs,as with the PDs 84.

The above described first through seventh embodiments of the presentdisclosure can be combined as appropriate.

Examples of Use of a Solid-State Imaging Device

FIG. 13 is a diagram showing examples of use of a solid-state imagingdevice according to any of the first through seventh embodiments of thepresent disclosure.

The above described solid-state imaging devices can be used in variouscases where light, such as visible light, infrared light, ultravioletlight, or X-rays, is to be sensed, as listed below, for example.

-   -   Devices configured to take images for appreciation activities,        such as digital cameras and portable devices with camera        functions.    -   Devices for transportation use, such as vehicle-mounted sensors        configured to take images of the front, the back, the        surroundings, the inside, and the like of an automobile to        perform safe driving like an automatic stop or recognize a        driver's condition and the like, surveillance cameras for        monitoring running vehicles and roads, and ranging sensors for        measuring distances between vehicles or the like.    -   Devices to be used in conjunction with home electric appliances,        such as television sets, refrigerators, and air conditioners, to        take images of gestures of users and operate the appliances in        accordance with the gestures.    -   Devices for medical care use and health care use, such as        endoscopes and devices for receiving infrared light for        angiography.    -   Devices for security use, such as surveillance cameras for crime        prevention and cameras for personal authentication.    -   Devices for beauty care use, such as skin measurement devices        configured to image the skin and microscopes for imaging the        scalp.    -   Devices for sporting use, such as action cameras and wearable        cameras for sports and the like.    -   Devices for agricultural use such as cameras for monitoring        conditions of fields and crops.

Note that embodiments of the present disclosure are not limited to theabove described embodiments, and various modifications may be made tothem without departing from the scope of the present disclosure.

The present disclosure can also be embodied in the configurationsdescribed below.

(1)

A solid-state imaging device that has a first photoelectric conversionportion, an upper electrode, and a lower electrode formed outside asubstrate, the first photoelectric conversion portion performingphotoelectric conversion in accordance with incident light, the upperelectrode and the lower electrode being formed to sandwich the firstphotoelectric conversion portion,

the solid-state imaging device including:

an aperture pixel that is disposed on a pixel array, and generates anormal pixel signal;

an OPB pixel that is disposed at an end portion on the pixel array, andgenerates a pixel signal indicating a dark current component; and

a charge releasing portion that is disposed between the aperture pixeland the OPB pixel, and releases electric charge flowing out from theaperture pixel.

(2)

The solid-state imaging device according to (1), in which the chargereleasing portion is a dummy pixel disposed between the aperture pixeland the OPB pixel, and the lower electrode corresponding to the dummypixel is fixed at a constant voltage.

(3)

The solid-state imaging device according to (1) or (2), in which thelower electrode corresponding to the dummy pixel is connected to a powersupply voltage wiring line.

(4)

The solid-state imaging device according to any of (1) to (3), in whichthe lower electrode corresponding to the dummy pixel is connected to apower supply voltage wiring line via a control transistor that is alwayson.

(5)

The solid-state imaging device according to any of (2) to (4), in whichat least one pixel of the dummy pixel is disposed between the aperturepixel and the OPB pixel.

(6)

The solid-state imaging device according to any of (2) to (5), in whichthe dummy pixel is disposed to surround a region where the aperturepixel is disposed.

(7)

The solid-state imaging device according to (1), in which the chargereleasing portion is formed with the lower electrode fixed at a constantvoltage.

(8)

The solid-state imaging device according to (7), in which the chargereleasing portion formed with the lower electrode fixed at a constantvoltage is disposed around each aperture pixel.

(9)

The solid-state imaging device according to any of (1) to (8), furtherincluding

a second photoelectric conversion portion that is formed in thesubstrate, and has a different wavelength band for photoelectricconversion from a wavelength band of the first photoelectric conversionportion.

(10)

The solid-state imaging device according to (9), in which the secondphotoelectric conversion portion corresponding to the dummy pixel isconnected to a power supply voltage wiring line.

(11)

The solid-state imaging device according to (9) or (10), in which thesecond photoelectric conversion portion corresponding to the dummy pixelis connected to an FD via a control transistor that is always on.

(12)

The solid-state imaging device according to any of (1) to (11), furtherincluding

a third photoelectric conversion portion that is formed in thesubstrate, and has a different wavelength band for photoelectricconversion from the wavelength bands of the first and secondphotoelectric conversion portions.

(13)

The solid-state imaging device according to (12), in which the thirdphotoelectric conversion portion corresponding to the dummy pixel isconnected to a power supply voltage wiring line.

(14)

The solid-state imaging device according to (12) or (13), in which thethird photoelectric conversion portion corresponding to the dummy pixelis connected to an FD via a control transistor that is always on.

(15)

The solid-state imaging device according to any of (1) to (14), furtherincluding

a light shielding portion that shields the charge releasing portion andthe OPB pixel from light.

(16)

The solid-state imaging device according to any of (1) to (15), which isof a back-illuminated type.

(17)

An electronic apparatus on which a solid-state imaging device ismounted, the solid-state imaging device having a first photoelectricconversion portion, an upper electrode, and a lower electrode formedoutside a substrate, the first photoelectric conversion portionperforming photoelectric conversion in accordance with incident light,the upper electrode and the lower electrode being formed to sandwich thefirst photoelectric conversion portion,

the solid-state imaging device including:

an aperture pixel that is disposed on a pixel array, and generates anormal pixel signal;

an OPB pixel that is disposed at an end portion on the pixel array, andgenerates a pixel signal indicating a dark current component; and

a charge releasing portion that is disposed between the aperture pixeland the OPB pixel, and releases electric charge flowing out from theaperture pixel.

REFERENCE SIGNS LIST

-   14 Si substrate-   17 Wiring layer-   19 Light shielding film-   40 Solid-state imaging device-   41 Aperture pixel-   42 OPB pixel-   43 Dummy pixel-   51 Organic photoelectric conversion film-   52 Upper electrode-   53 Lower electrode-   54 FD-   55 Reset gate-   60 Solid-state imaging device-   61 Aperture pixel-   62 OPB pixel-   63 Dummy pixel-   64 Connecting portion-   70 Solid-state imaging device-   71 Aperture pixel-   72, 72′ OPB pixel-   73 Drain portion-   74 Lower electrode-   80 Solid-state imaging device-   81 Aperture pixel-   82 OPB pixel-   83 Dummy pixel-   84 PD-   90 Solid-state imaging device-   91 Aperture pixel-   92 OPB pixel-   93 Dummy pixel-   94 PD-   100 Solid-state imaging device-   101 Aperture pixel-   102 OPB pixel-   103 Dummy pixel-   105 FD-   106 Transfer gate-   120 Solid-state imaging device-   121 Aperture pixel-   122 OPB pixel-   123 Dummy pixel-   124 Connecting portion

The invention claimed is:
 1. A solid-state imaging device, comprising: asubstrate; a first photoelectric conversion portion; a secondphotoelectric conversion portion in the substrate; an upper electrode; alower electrode, wherein the first photoelectric conversion portion, theupper electrode, and the lower electrode are outside the substrate, thefirst photoelectric conversion portion and the second photoelectricconversion portion are configured to perform photoelectric conversionbased on incident light, the first photoelectric conversion portion isbetween the upper electrode and the lower electrode, the firstphotoelectric conversion portion has a first wavelength band for thephotoelectric conversion, the second photoelectric conversion portionhas a second wavelength band for the photoelectric conversion, and thefirst wavelength band of the first photoelectric conversion portion isdifferent from the second wavelength band of the second photoelectricconversion portion; an aperture pixel on a pixel array, wherein theaperture pixel is configured to generate a normal pixel signal; anOptical Black (OPB) pixel at an end portion of the pixel array, whereinthe OPB pixel is configured to generate a pixel signal indicating a darkcurrent component; and a dummy pixel between the aperture pixel and theOPB pixel, wherein the dummy pixel is configured to release electriccharge that flows out from the aperture pixel, the lower electrodecorresponds to the dummy pixel, and the lower electrode is at a constantvoltage.
 2. The solid-state imaging device according to claim 1, whereinthe lower electrode corresponding to the dummy pixel is connected to apower supply voltage wiring line.
 3. The solid-state imaging deviceaccording to claim 2, wherein the lower electrode corresponding to thedummy pixel is connected to the power supply voltage wiring line via acontrol transistor.
 4. The solid-state imaging device according to claim1, wherein at least two dummy pixels are between the aperture pixel andthe OPB pixel.
 5. The solid-state imaging device according to claim 1,wherein the aperture pixel is within a specific region, and the dummypixel surrounds the specific region.
 6. The solid-state imaging deviceaccording to claim 1, wherein the dummy pixel is around the aperturepixel.
 7. The solid-state imaging device according to claim 1, whereinthe second photoelectric conversion portion corresponding to the dummypixel is connected to a power supply voltage wiring line.
 8. Thesolid-state imaging device according to claim 1, wherein the secondphotoelectric conversion portion corresponding to the dummy pixel isconnected to a Floating Diffusion (FD) via a control transistor.
 9. Thesolid-state imaging device according to claim 1, further comprising athird photoelectric conversion portion in the substrate, wherein thethird photoelectric conversion portion has a third wavelength band forthe photoelectric conversion, and the third wavelength band is differentfrom the first wavelength band and the second wavelength band.
 10. Thesolid-state imaging device according to claim 9, wherein the thirdphotoelectric conversion portion corresponding to the dummy pixel isconnected to a power supply voltage wiring line.
 11. The solid-stateimaging device according to claim 9, wherein the third photoelectricconversion portion corresponding to the dummy pixel is connected to aFloating Diffusion (FD) via a control transistor.
 12. The solid-stateimaging device according to claim 1, further comprising a lightshielding portion configured to shield the dummy pixel and the OPB pixelfrom the incident light.
 13. The solid-state imaging device according toclaim 1, wherein the solid-state imaging device is of a back-illuminatedtype.
 14. An electronic apparatus, comprising: a solid-state imagingdevice that includes: a substrate; a first photoelectric conversionportion; a second photoelectric conversion portion in the substrate; anupper electrode; a lower electrode, wherein the first photoelectricconversion portion, the upper electrode, and the lower electrode areoutside the substrate, the first photoelectric conversion portion andthe second photoelectric conversion portion are configured to performphotoelectric conversion based on incident light, the firstphotoelectric conversion portion is between the upper electrode and thelower electrode, the first photoelectric conversion portion has a firstwavelength band for the photoelectric conversion, the secondphotoelectric conversion portion has a second wavelength band for thephotoelectric conversion, and the first wavelength band of the firstphotoelectric conversion portion is different from the second wavelengthband of the second photoelectric conversion portion; an aperture pixelon a pixel array, wherein the aperture pixel is configured to generate anormal pixel signal; an Optical Black (OPB) pixel at an end portion ofthe pixel array, wherein the OPB pixel is configured to generate a pixelsignal indicating a dark current component; and a dummy pixel betweenthe aperture pixel and the OPB pixel, wherein the dummy pixel isconfigured to release electric charge that flows out from the aperturepixel, the lower electrode corresponds to the dummy pixel, and the lowerelectrode is at a constant voltage.
 15. A solid-state imaging device,comprising: a substrate; a first photoelectric conversion portion; asecond photoelectric conversion portion in the substrate; a thirdphotoelectric conversion portion in the substrate; an upper electrode; alower electrode, wherein the first photoelectric conversion portion, theupper electrode, and the lower electrode are outside the substrate, thefirst photoelectric conversion portion, the second photoelectricconversion portion, and the third photoelectric conversion portion areconfigured to perform photoelectric conversion based on incident light,the first photoelectric conversion portion is between the upperelectrode and the lower electrode, the first photoelectric conversionportion has a first wavelength band for the photoelectric conversion,the second photoelectric conversion portion has a second wavelength bandfor the photoelectric conversion, the third photoelectric conversionportion has a third wavelength band for the photoelectric conversion,and the third wavelength band is different from the first wavelengthband and the second wavelength band; an aperture pixel on a pixel array,wherein the aperture pixel is configured to generate a normal pixelsignal; an Optical Black (OPB) pixel at an end portion on the pixelarray, wherein the OPB pixel is configured to generate a pixel signalindicating a dark current component; and a dummy pixel between theaperture pixel and the OPB pixel, wherein the dummy pixel is configuredto release electric charge that flows out from the aperture pixel, thelower electrode corresponds to the dummy pixel, and the lower electrodeis at a constant voltage.